/***
 * 创建透明图
 */
export function useTransparencyDrawing(width: number, height: number): string {
    const canvas: HTMLCanvasElement = document.createElement('canvas')
    canvas.width = width
    canvas.height = height
    const ctx: CanvasRenderingContext2D | null = canvas.getContext('2d')
    if (ctx) {
        ctx.fillStyle = 'rgba(0, 0, 0, 0)'
        ctx.fillRect(0, 0, width, height)
        const base64: string = canvas.toDataURL('image/png')
        canvas.remove()
        return base64
    }
    return ''
}

